When a client is ordering a custom-made item, there are typically multiple parameters to be specified. Further, the parameters may have a wide variety of interrelationships, where choosing one parameter can restrict or broaden other parameter options. For example, different manufacturers may offer different models of an item. Thus, if a client is presented with a list of manufacturers of a product and the client chooses a particular manufacturer, the client may also select a particular parameter for the item that the selected manufacturer cannot provide. Thus, current systems for generating product or service orders can lead to incomplete specification of an order, miscommunication between client and provider, and incompatible parameters being selected, among other problems. This presents a challenge for organizing information in a system for generating item orders.